vfs: spread struct mount - shared subtree iterators
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 25 Nov 2011 04:56:26 +0000 (23:56 -0500)
committerAl Viro <viro@zeniv.linux.org.uk>
Wed, 4 Jan 2012 03:57:07 +0000 (22:57 -0500)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/pnode.c

index 29e366dec02454051b7759e3090a2892902e2d36..f86cd4bc31ce6ed497f5679e1be711cbeb9ad841 100644 (file)
 #include "pnode.h"
 
 /* return the next shared peer mount of @p */
-static inline struct vfsmount *next_peer(struct vfsmount *p)
+static inline struct mount *next_peer(struct mount *p)
 {
-       return list_entry(p->mnt_share.next, struct vfsmount, mnt_share);
+       return list_entry(p->mnt.mnt_share.next, struct mount, mnt.mnt_share);
 }
 
-static inline struct vfsmount *first_slave(struct vfsmount *p)
+static inline struct mount *first_slave(struct mount *p)
 {
-       return list_entry(p->mnt_slave_list.next, struct vfsmount, mnt_slave);
+       return list_entry(p->mnt.mnt_slave_list.next, struct mount, mnt.mnt_slave);
 }
 
-static inline struct vfsmount *next_slave(struct vfsmount *p)
+static inline struct mount *next_slave(struct mount *p)
 {
-       return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave);
+       return list_entry(p->mnt.mnt_slave.next, struct mount, mnt.mnt_slave);
 }
 
 static struct mount *get_peer_under_root(struct mount *mnt,
@@ -39,7 +39,7 @@ static struct mount *get_peer_under_root(struct mount *mnt,
                if (m->mnt.mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root))
                        return m;
 
-               m = real_mount(next_peer(&m->mnt));
+               m = next_peer(m);
        } while (m != mnt);
 
        return NULL;
@@ -74,11 +74,11 @@ static int do_make_slave(struct mount *mnt)
         * same root dentry. If none is available then
         * slave it to anything that is available.
         */
-       while ((peer_mnt = real_mount(next_peer(&peer_mnt->mnt))) != mnt &&
+       while ((peer_mnt = next_peer(peer_mnt)) != mnt &&
               peer_mnt->mnt.mnt_root != mnt->mnt.mnt_root) ;
 
        if (peer_mnt == mnt) {
-               peer_mnt = real_mount(next_peer(&mnt->mnt));
+               peer_mnt = next_peer(mnt);
                if (peer_mnt == mnt)
                        peer_mnt = NULL;
        }
@@ -141,21 +141,20 @@ void change_mnt_propagation(struct mount *mnt, int type)
  * vfsmount found while iterating with propagation_next() is
  * a peer of one we'd found earlier.
  */
-static struct vfsmount *propagation_next(struct vfsmount *m,
-                                        struct vfsmount *origin)
+static struct mount *propagation_next(struct mount *m,
+                                        struct mount *origin)
 {
        /* are there any slaves of this mount? */
-       if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list))
+       if (!IS_MNT_NEW(&m->mnt) && !list_empty(&m->mnt.mnt_slave_list))
                return first_slave(m);
 
        while (1) {
-               struct vfsmount *next;
-               struct vfsmount *master = m->mnt_master;
+               struct mount *master = real_mount(m->mnt.mnt_master);
 
-               if (master == origin->mnt_master) {
-                       next = next_peer(m);
-                       return ((next == origin) ? NULL : next);
-               } else if (m->mnt_slave.next != &master->mnt_slave_list)
+               if (&master->mnt == origin->mnt.mnt_master) {
+                       struct mount *next = next_peer(m);
+                       return (next == origin) ? NULL : next;
+               } else if (m->mnt.mnt_slave.next != &master->mnt.mnt_slave_list)
                        return next_slave(m);
 
                /* back at master */
@@ -172,25 +171,25 @@ static struct vfsmount *propagation_next(struct vfsmount *m,
  * @type       return CL_SLAVE if the new mount has to be
  *             cloned as a slave.
  */
-static struct vfsmount *get_source(struct vfsmount *dest,
-                                       struct vfsmount *last_dest,
-                                       struct vfsmount *last_src,
-                                       int *type)
+static struct mount *get_source(struct mount *dest,
+                               struct mount *last_dest,
+                               struct mount *last_src,
+                               int *type)
 {
-       struct vfsmount *p_last_src = NULL;
-       struct vfsmount *p_last_dest = NULL;
+       struct mount *p_last_src = NULL;
+       struct mount *p_last_dest = NULL;
 
-       while (last_dest != dest->mnt_master) {
+       while (&last_dest->mnt != dest->mnt.mnt_master) {
                p_last_dest = last_dest;
                p_last_src = last_src;
-               last_dest = last_dest->mnt_master;
-               last_src = last_src->mnt_master;
+               last_dest = real_mount(last_dest->mnt.mnt_master);
+               last_src = real_mount(last_src->mnt.mnt_master);
        }
 
        if (p_last_dest) {
                do {
                        p_last_dest = next_peer(p_last_dest);
-               } while (IS_MNT_NEW(p_last_dest));
+               } while (IS_MNT_NEW(&p_last_dest->mnt));
                /* is that a peer of the earlier? */
                if (dest == p_last_dest) {
                        *type = CL_MAKE_SHARED;
@@ -200,7 +199,7 @@ static struct vfsmount *get_source(struct vfsmount *dest,
        /* slave of the earlier, then */
        *type = CL_SLAVE;
        /* beginning of peer group among the slaves? */
-       if (IS_MNT_SHARED(dest))
+       if (IS_MNT_SHARED(&dest->mnt))
                *type |= CL_MAKE_SHARED;
        return last_src;
 }
@@ -221,32 +220,31 @@ static struct vfsmount *get_source(struct vfsmount *dest,
 int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry,
                    struct vfsmount *source_mnt, struct list_head *tree_list)
 {
-       struct vfsmount *m;
-       struct mount *child;
+       struct mount *m, *child;
        int ret = 0;
-       struct vfsmount *prev_dest_mnt = dest_mnt;
-       struct vfsmount *prev_src_mnt  = source_mnt;
+       struct mount *prev_dest_mnt = real_mount(dest_mnt);
+       struct mount *prev_src_mnt  = real_mount(source_mnt);
        LIST_HEAD(tmp_list);
        LIST_HEAD(umount_list);
 
-       for (m = propagation_next(dest_mnt, dest_mnt); m;
-                       m = propagation_next(m, dest_mnt)) {
+       for (m = propagation_next(real_mount(dest_mnt), real_mount(dest_mnt)); m;
+                       m = propagation_next(m, real_mount(dest_mnt))) {
                int type;
-               struct vfsmount *source;
+               struct mount *source;
 
-               if (IS_MNT_NEW(m))
+               if (IS_MNT_NEW(&m->mnt))
                        continue;
 
                source =  get_source(m, prev_dest_mnt, prev_src_mnt, &type);
 
-               if (!(child = copy_tree(real_mount(source), source->mnt_root, type))) {
+               if (!(child = copy_tree(source, source->mnt.mnt_root, type))) {
                        ret = -ENOMEM;
                        list_splice(tree_list, tmp_list.prev);
                        goto out;
                }
 
-               if (is_subdir(dest_dentry, m->mnt_root)) {
-                       mnt_set_mountpoint(m, dest_dentry, child);
+               if (is_subdir(dest_dentry, m->mnt.mnt_root)) {
+                       mnt_set_mountpoint(&m->mnt, dest_dentry, child);
                        list_add_tail(&child->mnt_hash, tree_list);
                } else {
                        /*
@@ -256,7 +254,7 @@ int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry,
                        list_add_tail(&child->mnt_hash, &tmp_list);
                }
                prev_dest_mnt = m;
-               prev_src_mnt  = &child->mnt;
+               prev_src_mnt  = child;
        }
 out:
        br_write_lock(vfsmount_lock);
@@ -290,8 +288,7 @@ static inline int do_refcount_check(struct mount *mnt, int count)
  */
 int propagate_mount_busy(struct mount *mnt, int refcnt)
 {
-       struct vfsmount *m;
-       struct mount *child;
+       struct mount *m, *child;
        struct mount *parent = mnt->mnt_parent;
        int ret = 0;
 
@@ -306,9 +303,9 @@ int propagate_mount_busy(struct mount *mnt, int refcnt)
        if (!list_empty(&mnt->mnt_mounts) || do_refcount_check(mnt, refcnt))
                return 1;
 
-       for (m = propagation_next(&parent->mnt, &parent->mnt); m;
-                       m = propagation_next(m, &parent->mnt)) {
-               child = __lookup_mnt(m, mnt->mnt_mountpoint, 0);
+       for (m = propagation_next(parent, parent); m;
+                       m = propagation_next(m, parent)) {
+               child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint, 0);
                if (child && list_empty(&child->mnt_mounts) &&
                    (ret = do_refcount_check(child, 1)))
                        break;
@@ -323,14 +320,14 @@ int propagate_mount_busy(struct mount *mnt, int refcnt)
 static void __propagate_umount(struct mount *mnt)
 {
        struct mount *parent = mnt->mnt_parent;
-       struct vfsmount *m;
+       struct mount *m;
 
        BUG_ON(parent == mnt);
 
-       for (m = propagation_next(&parent->mnt, &parent->mnt); m;
-                       m = propagation_next(m, &parent->mnt)) {
+       for (m = propagation_next(parent, parent); m;
+                       m = propagation_next(m, parent)) {
 
-               struct mount *child = __lookup_mnt(m,
+               struct mount *child = __lookup_mnt(&m->mnt,
                                        mnt->mnt_mountpoint, 0);
                /*
                 * umount the child only if the child has no